Early Intervention to Reduce Bone Loss After Spinal Cord Injury

After a complete spinal cord injury (SCI), the patient becomes wheelchair-dependent, and the associated lack of weight-bearing and inactivity of paralysed muscles can lead to extensive bone loss in the long bones of the legs. It has been documented that the most rapid phase of bone loss is during the first year, but bone loss can continue for a number of years post-injury, leading to an increased risk of fracture in chronic SCI. Through a previous longitudinal study, in which we described rates of bone loss in the first year of SCI using peripheral Quantitative Computed Tomography (pQCT), we showed that there is a subset of patients who suffer from extremely rapid bone loss, losing up to 50% of their bone mineral density (BMD) in the first 12 months post-SCI. As a result of this work, we now know that, by performing repeat bone scans within months of injury, we are able to detect and "red-flag" those patients at highest risk of rapidly weakening bones. We propose that, once these patients have been identified, there is an opportunity to intervene with bone-stimulating interventions within months of injury, before BMD reaches dangerously low values. In this new phase of the research, therefore, we are introducing an intervention phase to the longitudinal pQCT study. For this, we aim to trial a physical intervention, Whole Body Vibration (WBV), that could potentially reduce rates of further bone loss in fast bone losers. Vibration would achieve this by acting as a mechanical stimulus for bone cells, to encourage bone formation. If shown to be successful as an early bone-stimulating intervention, it may prove to be a tool for reducing future fracture risk in patients with SCI.